Stabilized liquid hydrocarbon



Patented m 28, 1942" 2,290,872 STD LIQUID HYDROCARBON Delton R. Frey,

The Lubri-Zol Corporation,

corporation of Ohio East Cleveland, Ohio,

assignor to Wicklifle, Ohio, at

No Drawing. Application March 30, 1939, Serial No. 265,051

7 Claims. (Cl. 252-32) This invention relates, as indicated, to the stabilization of liquid hydrocarbon compositions. The term liquid hydrocarbon compositions as used herein is intended to include liquid compositions which are essentially derivatives of petroleum, naturally occurring oils of the types represented by animal, vegetable and marine oil and derivatives of the same.

More specifically this invention relates to the stabilization of liquid hydrocarbon compositions which are essentially mineral oil and particularly mineral oil of the character commonly employed as lubricants. My invention, however, is likewise applicable to the stabilization of lighter fractions of petroleum such as are used for fuels. Liquid hydrocarbon compositions of the character above identified are subject during storage, handling and particularly during use, to deterioration which may be occasioned either by oxidation or polymerization, and such deterioration usually proceeds at an accelerated rate when, for example, the liquid hydrocarbon composition is subjected to elevated temperatures and similar conditions encountered when the same are used as lubricants in internal combustion engines.

This deterioration, which, as indicated, may occur either during storage, handling or use, is generally manifested by discoloration of the liquid hydrocarbon body; generation within the body of fiocculent material; the precipitation from the body of the more serious types of deterioration products such as sludge; and the deposit of varnish or shellac-like deposits on metallic surfaces with which the compositions come in contact especially during use.

Inasmuch as deterioration is usually accelerated by the severe conditions, such as temperature, to which the hydrocarbon composition is subjected, it will be observed that my invention is particularly suited for the stabilization of hydrocarbon compositions such as mineral lubricating oils used as the lubricant in the crank case of internal comubustion engines whether of the ignition or Diesel type. My invention is particularly applicable to the stabilization of lubricants used in Diesel engines on account of the more severe stresses to which the lubricating composition is subjected in that type of engine.

It is a principal object of my invention therefore to provide for the stabilization of compositions of the character defined in order to reduce the tendency of the same to decomposition, particularly in the manner indicated.

It will also be observed that the addition agents employed for the described purposes, especially when prepared in the manner hereinafter more specifically defined, are in themselves new compositions of matter.

Other objects of my invention will appear as the description proceeds.

My invention, then, consists of the steps hereinafter fully described and particularly pointed out in the claims, the following description setting forth in detail certain steps embodying the invention, such disclosed steps constituting, however, but one of the various ways in which the principle of the invention may be used.

Broadly stated, this invention comprises the stabilization of liquid hydrocarbon compositions of the character previously identified, by the inclusion therein of a minor proportion of a compound of the class represented .by tricyclohexyl phosphite, and more especially by the inclusion therein of minor proportions of oil-soluble phosphorous-bearing products resulting from the reaction of phosphorus tri-chloride (PCla) with a compound of the class consisting of cyclohexanol, homologs of cyclohexanol, mixtures of cyclohexanol and its homologs andmixtures of homologs of cyclohexanol.

The addition agents which may be employed in minor proportions for the stabilization of liquid hydrocarbon compositions in accordance with my invention may be certain derivatives of the aforementioned products or portions of the aforementioned reaction products, which derivatives may be prepared, for example, by halogenation and/or treatment with an alkali or other base to form a salt or ester-salt.

It is likewise within the contemplation of my invention to employ a reaction product of the character above identified which contains a minor amount of combined halogen, specifically chlorine, present therein either as a result of direct halogenation of the product as above indicated, or by the inclusion therein of combined halogen as a result of the reaction with phosphorus tri-chloride.

The following are illustrative of specific embodiment of my invention:

A material which for purposes of convenience in referring to the same herein we shall designate as P. C. Y. is prepared by the reaction of a commercial grade f cyclohexanol with PCla. The commercial grade of cyclohexanol employed contained in addition to cyclohexanol minor amounts of certain of the homologs thereof such as methyl cyclohexanol.

The relative proportions of this commercial grade of cyclohexanol and PCla usd in the preparation of P. C. Y. are given in the following table, as well as the properties of the end product:

Cyclohexanol 1,215 parts by weight PCls 2,655 parts by weight Weight of product "2,545 partsby weight Weight of material removed by distillation -514 parts by weight Percent yield based on The cyclohexanol is placed in a reaction vessel equipped with an agitator and reflux condenser. The vessel and agitator are preferably of glass or enamel. The PCla is added slowly and the temperature of the reactants maintained between 50 C. and 60 C. during the addition of the PC13. The mixture is stirred continuously during the addition of the PC13. The temperature of the reactants may be controlled by the rate of the addition of the P013. After all of the PC13 has been added in the manner above described the reacting materials are heated in a water bath to 100 C. and then by use of such water bath maintained at a temperature of 100 C. for three hours. The reactants are mechanically agitated throughout the periods of addition of PC13; elevation to 100 C.; and the three hour period while maintained at 100 After being maintained at 100 C. for three hours the reaction material is distilled at an alesolute pressure of eight inches of mercury and all materials boiling below C. are discarded. A sharp break in the Vapor temperature will be noted indicating completion or. the distillation of the low boiling fraction and the fact that the residue is the end product suitable for use. The material which is distilled over is probably largely minor amounts of unreacted PC13 and cyclohexanol. If desired the end product may be water washed since such water washing step will be found to remove a certain amount of ch1o rine which would otherwise remain. The properties of the composition given in the foregoing table are those for material which has been water washed.

We believe that the principal products of the reaction of PC13 with a compound of the class consisting of cyclohexanol and homologs of cyclohexanol are esters of phosphorous acid (such as (ROMP, (RO)2POH and ROP(OH)2, where R is the cyclohexyl radicle or a homolog of it), and that halogen-bearing derivatives of such esters may be also be formed, as well as other halogenbearing derivatives of ROH, for example RC]. It appears that the phosphorous-bearing constituents of the reaction product are responsible for the stabilizing effect when the product is used in accordance with our invention. However, for most purposes, the other constituents are not deleterious, and for some purposes may even be advantageously included. The phosphorous-bearing constituents are in general much less volatile than the other constituents; the latter may therefore be easily removed, if desired, by distillation at atmospheric or sub-atmospheric pressure.

The following table gives the results obtained by the addition of minor amounts of P.C.Y. prepared as above indicated to several different representative commercial oils and oils treated with other addition agents.

Composition Oxidation tests Conradson o Con-0' Example carbon Vis. in SUS at 210 F. Naphtha insclubles Ls10? No. Hexachlor 0*t11o Per diphenyl dicblor 22? {sutyl cent oxide benzene e S estate PC! Per cent Ori Final Ori At 48 vise Hrs. for Hrs. for 11 eight hours increase 10 mg. 100 me. 48 hrs.

MID-OONTINENT SAE 30 MOTOR OIL UNTREAIED 32 1.67 63.1 74.4 17.9 13.5 44 121 18 37 1. 16 62. 9 68. 8 9. 4 26. 5 I) 41 -.1(. .27 1.30 63.5 67.9 6.9 24.0 b {H .l5 .68 1.82 63.6 73.1 16.0 17 46 111 .51 45 1. 27 62. 7 67. 9 8. 3 22 b 79 22 41 2. 05 61. 6 72. 2 17. 2 13 45 118 0.! 40 1. 30 62. 1 69. 0 l1. 1 28. 5 I: 76 23 PENNSYLVANIA SAE 40 MOTOR OIL, UNTREATED 1. 25 3. 52 82. 7 104. 0 26. 3 a b 5 08 1.26 2.20 84.3 95.3 13.1 a b 3 31 1. 46 2. 31 81. 8 95. l 16. 3 a b 2 25 1. 67 3. 54 82. 3 104. 0 26. 5 a b 3 38 1.66 2. 61 82. 1 95. 2 16.0 a b 4 l6 1. 19 2. 79. 6 98. 9 24. 2 a b 6 35 1. 53 2. 41 81. 7 93. 6 14. 6 a b 2 18 PENNSYLVANIA SAE 10 MOTOR OIL, UNTREATED 23 94 46. 3 49. 6 7. 0 26. 0 b 54 75 .16 .52 46.1 47.7 3.5 43 b 12 .15 17 .43 46.2 48.3 4.6 39 b 11 15 .30 .15 1.40 46.3 50.6 9.3 22 b 65 -1.40 .3 .22 .58 46. 1 47.5 3.0 34.5 b 12 -.22 .50 .21 1.19 46.5 50.0 7.5 23.0 b --1.40 50 .18 .55 46.1 47.5 3.0 41.0 b 14 .23

u==did not produce 10 mg. in 48 hours. b=d1d not produce mg. in 48 hours.

The determinations which appear in the foregoing table, such as, for example, Conradson carbon, viscosity determinations, and naphtha insoluble, were determined on samples prepared by an oxidation test procedure which is in every respect similar to that prescribed by the Standard oi Indiana Oxidation Test, excepting that a piece of iron wire is submerged in the 011 during the test. The data given in the column headed "Corrosion" has been determined in accordance with the standard Shell corrosion test usi g lead bronze as the metal.

The effectiveness of P.C.Y. in improving the properties 01 a lubricating composition for use in internal combustion engines with particular regard to the stability of the lubricant during use has been demonstrated by tests conducted on a liquid-cooled single cylinder 4-cycle gasoline engine rated at 2 /2 H. P. at 1800 R. P. M. This engine was run at 1600 R. P. M. under a load of 2 H. P. for a period of 100 hours for each test. The cooling fiuid temperature was maintained at 250 F. and the temperature .of the lubricant in the crankcase at 225 F. The air-fuel ratio was adjusted to maintain a value of 12.7 to 1.

In the first test, a S. A. E. 20 motor oil having a viscosity index of about 105 was employed as the lubricant and in a second test, the same oil to which .03% of P. C. Y. was added was employed as a lubricant. The engine was fitted with new pistons and rings before the start of each test and after completion of the first test, the engine was taken down. thoroughly cleaned and fitted with a new piston and rings.

At the conclusion of the first test, nearly the entire skirt of the piston was very black, while at the end of the second test only 60% of the skirt showed only very light deposits of light brown material. The inside of the piston skirt at the end of the first test showed a light shellaclike deposit with a dark brown deposit on the vertical ribs while the inside of the piston skirt at the end of the second test showed no discoloration.

The liquid hydrocarbon compositions which may be stabilized by the use of the addition agents hereinbefore specificed need not be pure hydrocarbons but may contain other addition agents of the type commonly employed in hydrocarbons of the class specified above. In other words, when the hydrocarbon being stabilized is a mineral lubricating oil, it may advantageously contain other addition agents such as extreme pressure addition agents on the order of halogen, phosphorus and/or sulphur compounds, as well as corrosion inhibitors, such as other phosphorus compounds, etc; and other additions commonly employed, such as pour-point depressors and the like.

When a lighter fraction, as above indicated, is stabilized, the addition agents commonly employed in such lighter fractions may also be present, as for example, the various dopes commonly employed in Diesel fuels and antiknock compounds commonly employed in gasolines such as tetraethyl lead, iron carbonyl, etc.

In general, the addition agents of this invention will not be found incompatible with commonly employed anti-oxidants such as are used in gasolines and the like.

There may, however, be certain of these other addition agents which might be found incompatible with the addition agents of the present invention and in such cases, of course, the incompatible addition agent, whatever it may be, should be omitted, since it will usually be found that a compatible addition agent for the desired purpose will be available among others of those available.

Among the other addition agents with which the compounds of the present invention may be employed to advantag as above stated, are the extreme pressure addition agents, such as the halogen, phosphorus and/or sulfur-containing compounds.

In general, we have found that the addition agents of the present invention do not detrimentally affect the extreme pressure characteristics of a mineral lubricating oil, for example, which characteristics are the result of the presence therein of the extreme pressure addition agents above-named. Moreover, where the addition agents of the present invention have been tested in lubricating compositions which also contain certain other addition agents, the extreme pressure characteristics of the resultant composition has been somewhat improved and such improvement has been traceable to the presence therein of the compounds of the present inventlon.

Throughout the foregoing specification and in the appended claims, reference is made to oilsoluble" and by such term, as used herein, it is intended to indicate the ability of the addition agent to form not only true solutions with the oil to which the same are added, but also the ability to form therewith any form of substantially permanently homogeneous composition.

As indicated above, my invention also contemplates the use of oil-soluble derivatives of the addition agents above identified. Such derivatives include the oil-soluble salts and ester-salts which may be produced by substituting a metal or basic radicle for one or more of the alcohol derived radicles of the addition agent. This is conveniently accomplished by partly or completely saponifying the addition agent such as the PC13 reaction product, above identified, with an alkali (e. g., sodium, potassium, ammonium or substituted ammonium hydroxide) in aqueous solution. Similar salts and ester-salts of metal other than the alkyl metals may be formed directly by reacting the addition agent with the metallic base, or more readily by double decomposition of the alkyl salt (or ester-salt) with a salt of the other metal.

The reaction product of Feb prepared in the manner above described is for certain uses preferable over pure tricyclohexyl phosphite.

The amounts of the addition agents of the present invention employed in the stabilization of liquid hydrocarbons are fractions of one percent; in general ranging from about .O0l% to .5%. Preferably, the addition agents will beemployed in concentrations of from about .01% to .5%. Preferably, the addition agents will be employed in concentrations of from about .01% to about .1%. The foregoing ranges of percentages are those which will be found best suited when stabilizing a hydrocarbon composition .of the type represented by mineral lubricating oil employed as the lubricantin the crank case of internal combustion engines. As previously indicated, these same addition agents may be employed for the purpose of stabilizing lighter fractions such as fuels, and when such lighter fractions are being stabilized concentrations in excess of those given above, i. e., ranging from the low limits above given up to about 1% by volume may be employed.

It will be found that the products resulting from the reaction of PO13 with homologs of cyclohexanol and particularly mixtures of such homologs and mixtures of such homologs with cyclohexanol will produce addition agents which are quite preferable over the remaining addition agents of the class previously identified. The halogen-containing reaction products, whether such halogen is present as a result of the P013 reaction or introduced by direct halogenation, will be found to give decidedly improved results. In view of the character of the reaction products of P013 with the homologs of cyclohexanol as well as the halogen-bearing derivatives above referred to, they may be employed in concentrations considerably greater than those previously specified for the entire class of compounds which may be employed as addition agents. In general, the reaction products of the homologs and the halogen-bearing derivatives above identified may be employed advantageously up to the limit of -their oil solubility, although generally, on account of their cost, a minor amount, and usually below 20%, of these materials will be found sufficient to produce the desired results.

Throughout the foregoing description where halogens have been referred to, it is to be understood that the chlorinated species are very much preferred although the brominated and fluorinated species will also be found to have utility for particular uses.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the composition and method herein disclosed, provided the ingredients or steps stated by any of the following claims or the equivalent of such stated ingredients or steps be employed.

. I therefore particularly point out and distinctly claim as my invention:

1. A liquid hydrocarbon composition of the type which is otherwise subject to deterioration as by oxidation or polymerization, which has been substantially stabilized against such deterioration by the inclusion therein of a fraction of one percent, at least .001%, of an oil-soluble compound of the class consisting of:

(a) the reaction products of P013 with a compound of the class consisting of cyclohexanol,

homologs of cyclohexanol,

mixtures of cyclohexanol homologs,

mixtures of homologs of cyclohexanol;

and its (b) halogen-bearing derivatives of any of the foregoing;

(c) salts derived from any of the foregoing; and

(d) ester-salts derived from any of the foregoing.

(a) the reaction products of a reagent consisting of P013 with an organic material consisting of a compound of the class consisting of aacaera cyclohexanol,

homologs of cyclohexanol,

mixtures of cyclohexanol and its homologs,

mixtures of homologs of cyclohexanol:

(b) halogen-bearing derivatives of any of the foregoing;

(c) salt derived from any of the foregoing; and (d) ester-salt derived from any of the foregoing.

3. A liquid hydrocarbon composition of the type which is otherwise subject to deterioration as by oxidation or polymerization, which has been substantially stabilized against such deterioration by the inclusion therein of from about .01% to about .1 of an oil-soluble compound of the class consisting of: i

the reaction products of a reagent consisting of P013 with an organic material consisting of a compound of the class consisting of cyclohexanol,

homologs of cyclohexanol,

mixtures of cyclohexanol and its homologs, mixtures of homologs of cyclohexanol.

4. A liquid hydrocarbon composition of the type which is otherwise subject to deterioration as by oxidation or polymerization, which has been substantially stabilized against such deterioration by the inclusion therein of a minor amount of an oil-soluble compound of the class consisting of:

the reaction products of PC13 with a compound of the class consisting of homologs of cyclohexanol, mixtures of cyclohexanol and its homologs, mixtures of homologs of cyclohexanol.

5. A liquid hydrocarbon composition of the type which is otherwise subject to deterioration as by oxidation or polymerization, which has been substantially stabilized against such deterioration by the inclusion therein of a minor amount of an oil-soluble compound of the class consisting of halogen bearing derivatives of:

the reaction products of P013 with a compound of the class consisting of:

cyclohexanol,

homologs of cyclohexanol,

mixtures of cyclohexanol and its homologs, mixtures of homologs of cyclohexanol.

(a) the reaction products of PC13 with a compound of the class consisting of cyclohexanol,

homologs of cyclohexanol,

mixtures of cyclohexanol homologs,

mixtures of homologs of cyclohexanol:

and its (12) halogen-bearing derivatives of any of the foregoing.

7. A liquid hydrocarbon composition of the type which is otherwise subject to deterioration as by oxidation or polymerization, which has been substantially stabilized against such deterioration by the inclusion therein of a minor amount of an oil-soluble compound of the class consisting of ester salts of:

(a) the reaction products of PCla with a compound of the class consisting of cyclohexanol,

homologs of cyclohexanol,

mixtures of cyclohexanol and its homologs,

mixtures of homologs of cyclohexanol;

(b) halogen-bearing derivatives of any of the foregoing.

DELTON R. FREY. 

